Motor-less automatic extraction device surveiling inside of furnaces

ABSTRACT

The present invention relates to a motor-less automatic retraction device that can insert a vision tube capable of monitoring the inside of a furnace to mange the internal state of the furnace and control the temperature of the furnace into the furnace and retract the vision tube from the furnace in a motor-less manner. A conventional retraction device is disadvantageous in that it is expensive, voluminous, difficult to install, thus requiring expert&#39;s help to install, and difficult to repair at the time of breakdown, and requires expensive repairing costs.  
     In order to overcome the above-described disadvantages, an object of the present invention is to develop a motor-less automatic retraction device that can insert the vision tube into the furnace and retract the vision tube from the furnace using a spring, so the device is easily to install due to its small size and lightweight, is easy to repair, and allows repairing costs to be reduced.

TECHNICAL FIELD

[0001] The present invention relates to a camera system for monitoringthe inside of a furnace that allows the inside of the furnace to beobserved so as to manage the internal state of the furnace and controlthe temperature of the furnace.

BACKGROUND ART

[0002] In general, industrial furnaces are classified into various typesaccording to products produced by the furnaces.

[0003] For example, the furnace types include an industrial incineratorfor incinerating wastes, a melting furnace for iron mills for meltingmetal, a gas furnace for melting glass, a cement furnace, a potteryfurnace and a calcining furnace.

[0004] One of operators' common demands relating to various furnaces isto frequently observe the inside of a furnace during the operation ofthe furnace using clear images.

[0005] Once a furnace is operated, the furnace is continuously operatedfor a certain period of time as long as a particular breakdown does notoccur. Accordingly, the inside of the furnace should be inspected byfrequently observing the inside of the furnace during the operation ofthe furnace.

[0006] A conventional method of observing the inside of an industrialfurnace is generally implemented by forming a hole having a certain sizethrough the wall of the furnace, placing a door in front of the hole tobe selectively opened and closed, and observing the inside of thefurnace through the hole using the naked eye with the door being opened.

[0007] Such a conventional method is used in about 70% of furnaces. Inorder to protect the eye and intercept strong visible rays whenobserving the inside of a furnace by the above-described method, a usershould use an additional face protector to which an infrared glass isattached.

[0008] However, the conventional method is disadvantageous in that thethermal efficiency of a furnace is reduced due to the forming of a holethrough the wall of the furnace, combustion mixture ratio can be changeddue to the inflow of outside air, a viewing angle for observing theinside of the furnace with the naked eye is restricted due to asmall-sized and long hole in the wall of the furnace, and an operatormay be burned.

[0009] In order to solve the above problems, there was proposed anotherconventional method of monitoring the inside of a furnace by forming ahole through the wall of the furnace, forming a window using quartz orheat-resistant glass, placing a camera and a camera protective housingoutside the window, and photographing images formed on the window usingthe camera and lenses.

[0010] However, this conventional method has a limitation in themonitoring of the inside of a furnace because only limited imagesobtained through the hole formed through the wall of the furnace can beobserved.

[0011] Additionally, the glass is strongly resistant to heat, but weakto impact, abrasion and corrosion. As time passes, dirt, such as sootgenerated by combustion in the inside of a furnace, adheres to theinside surface of the window, so the transparency of the window isdeteriorated and clear images cannot be obtained, thus the windowrequiring continuous maintenance.

[0012] This conventional method is more advantageous than the firstconventional method, but is not appropriate for a large-sized furnace,and a furnace's temperature must be controlled precisely.

[0013] There was proposed still another conventional method of insertingan image device called a lens tube into the inside of the furnace andobserving the inside of a furnace through a monitor.

[0014] In accordance with this conventional method, lenses are arrangedin a conventional lens tube 1 in a row, a camera protective housing 3 isconnected to the back of the lens tube 1, and a general camera isdisposed in the camera protective housing.

[0015] As illustrated in FIG. 1, the housing 4 is mounted on a cylinderrail 7 with a housing support 6 attached to the cylinder rail 8. Thelens tube 1 is inserted into a furnace by supplying compressed airthrough the compressed air supply valve 25 to the cylinder rail andtherefore moving the housing support 6 so as to photograph and monitorthe inside of the furnace. In the case of an abnormal situation, such asa checkup, a power failure or the interruption of compressed air, thelens tube 1 is retracted from the furnace by supplying compressed air tothe compressed air supply valve 25 disposed on the front portion of thecylinder rail so as to protect the lens tube 1 from high temperatureheat inside the furnace.

[0016] The image of the inside of the furnace is passed through lensesarranged in the lens tube 1 in a row, and transmitted in and formed inthe image sensor disposed in the camera protective housing 3.Thereafter, the image is passed through the electric control box 30 anddisplayed on a control center monitor 100, so the monitoring of theinside of the furnace is enabled.

[0017] In this case, since the inside of the furnace has a hightemperature, specially fabricated camera protective housing 3 and thelens tube 1 are cooled by compressed air supplied from the air controlbox 31 to protect them. Thereafter, the supplied compressed air isdischarged to the outside along a certain path.

[0018] However, since the system for monitoring the inside of thefurnace described above employs the cylinder type retraction device andthe camera protective housing 4, and therefore additional structures arerequired to fixedly attach them to the system, the system becomes large,power is required and so causes breakdown, and maintaining andpurchasing costs are high.

DISCLOSURE OF THE INVENTION

[0019] An object of the present invention is to develop a motor-lessautomatic retraction device that is capable of inserting a small-sizedlightweight vision tube 12 for monitoring the inside of a furnace intothe furnace and retracting it from the furnace.

[0020] In order to accomplish the above object, the present inventionemploys a lightweight vision tube 12 equipped with a small-sized camerainstead of a conventional lens tube 1 and a camera protective housing 3.

[0021] As illustrated in FIG. 3, in the case of repair, a power failureor the interruption of compressed air, a signal generated in a controlbox 14 is sent to an electric locking device 15 using a solenoid, so thevision tube 12 is automatically retracted in a motor-less manner, thusprotecting the lens tube 12 from high temperature heat inside thefurnace.

[0022] In this case, in order to protect the vision tube 12 beinginserted into the furnace from high temperature heat, compressed air issupplied from the control box 14 as shown in FIG. 5 and dischargedthrough the front portion of the vision tube.

[0023] In brief, the present invention provides a motor-less automaticretraction device for a vision tube for monitoring the inside of afurnace by which an operator can observe and monitor the images of theinside of the furnace through a monitor 100.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024]FIG. 1 is a schematic diagram showing a conventional furnacemonitoring system employing a retraction device using a cylinder and acamera protective housing according to an embodiment of the prior art;

[0025]FIG. 2 is a diagram showing another conventional furnacemonitoring system according to another embodiment of the prior art;

[0026]FIG. 3 is a schematic view of a motor-less automatic retractiondevice using a mainspring and a vision tube when a vision tube isinserted into the inside of a furnace, in accordance with the presentinvention;

[0027]FIG. 4 is a schematic view of a motor-less automatic retractiondevice using a mainspring and a vision tube when a vision tube isretracted from the inside of a furnace, in accordance with the presentinvention;

[0028]FIG. 5 is a view showing a construction of a system for monitoringthe inside of a furnace in accordance with an embodiment of the presentinvention; and

[0029]FIG. 6 is a rear view of the system for monitoring the inside ofthe furnace in accordance with the embodiment of the present invention.

DESCRIPTION OF REFERENCE NUMERALS OF PRINCIPAL PARTS

[0030]1: lens tube

[0031]3: camera protective housing

[0032]5: cylinder rail

[0033]6: housing support

[0034]8: cylinder

[0035]10: image input hole

[0036]11: front end lens

[0037]12: vision tube

[0038]12: vision tube

[0039]13: spring

[0040]14: control box

[0041]15: electric locking device

[0042]17: vision tube coupling bracket

[0043]18: carriage plate

[0044]20: wall sleeve

[0045]21: flange

[0046]22: frame

[0047]23: latch

[0048]25: compressed air supply valve

[0049]28: shock absorber

[0050]29: protective cap

[0051]30: electric control box

[0052]31: air control box

[0053]100: monitor

BEST MODE FOR CARRYING OUT THE INVENTION

[0054] With reference to the accompanying drawings, a system formonitoring the inside of a furnace according to the present invention isdescribed.

[0055] In order to monitor the inside of a furnace, a carriage plate 18connected to a coupling bracket 17 is coupled to a rail 19 as shown inFIG. 7, a wall sleeve 20 and a flange 21 of the vision tube 12 arebrought into contact with each other to prevent supplied compressed airfrom leaking, and an electric locking device 15 mounted on a frame 22and a latch 23 mounted on the coupling bracket 17 are interlocked witheach other.

[0056] As shown in FIG. 3, the vision tube 12 is inserted into anentrance of the furnace with a spring 13 fixedly attached at its one endto the coupling bracket 17 and at its other end to the frame 22. In thepresent invention, the lens tube is automatically retracted from theinside of a furnace by the elasticity of the spring 13 in a non-powermanner, rather than by a cylinder or motor requiring power supply.

[0057] In the above case, the electric locking device 15 functions toprevent the vision tube 12 from being randomly retracted by theelasticity of the spring fastened to the frame 22, and to allow theautomatic retraction of the vision tube 12 by detecting an abnormalsituation such as the switch manipulation of an operator for automaticretraction, a power failure or the interruption of compressed air andunlock the electric locking device 15 and the latch 23 mounted on thecoupling bracket 17.

[0058] An image of the inside of a furnace intended to be observedpasses through an object lens 16 via a small hole formed in the front ofthe vision tube 12, sent to a detachable eye piece made in a convex lensand relay lenses 1, passes through an optical attenuation filter, sentto the control box 14 through the small-sized camera positioned behindthe vision tube 12, and transmitted to the monitor 100 of a centralcontrol center, thus allowing the inside of the furnace to be monitoredby an operator.

[0059] In addition, the present invention cools the vision tube withcompressed air to protect the vision tube 12 inserted into the furnacefrom high temperature heat.

[0060] In this case, the compressed air used to protect the vision tubeis supplied at a site, sent to the control box 14, purified in thecontrol box 14 through a filter to remove dirt, and supplied at constantpressure through a pressure switch.

[0061] The supplied compressed air is sent to a compressed air supplyvalve 25 connected to the rear end of the vision tube through acompressed air supply pipe, supplied to the vision tube 12 and thecompressed air valve 25 of the wall sleeve 20 mounted on the wall of thefurnace to protect the vision tube 12, passed through a space betweenthe vision tube 12 and the hole of the furnace, and discharged into thefurnace through the vision tube 12, thus allowing the vision tube 12 toresist high temperature heat using a cooling effect generated by thedischarging of the compressed air.

[0062]FIG. 4 is a schematic view of a motor-less automatic retractiondevice using a mainspring and a vision tube when a vision tube isretracted from the inside of a furnace, in accordance with the presentinvention. When the operator manipulates the switch of the control box14 to manually retract the vision tube for the repairing of the visiontube providing the images of the inside of the furnace, compressed airis not supplied to the vision tube or compressed air is supplied at lessthan a certain pressure, the pressure switch contained in the controlbox 14 detects the state and automatically transmits a signal to theelectric locking device 15 and the electric locking device 15 unlocksthe system, so the vision tube 12 is automatically retracted by theelasticity of the spring in a motor-less manner.

[0063] In that case, in order to protect the vision tube retracted bythe elasticity of the spring, a shock absorber is mounted on the frame22 at a position to which the coupling bracket 17 of the vision tube 12retracted to buffer impact.

[0064] In order to protect persons or the like from flames dischargedfrom the inside of the furnace due to a pressure difference, at the sametime that the vision tube is automatically retracted and passed throughthe entrance of the wall sleeve 20, a cap 29 automatically blocks theentrance of the wall sleeve 20 and intercepts flames.

INDUSTRIAL APPLICABILITY

[0065] A motor-less automatic retraction device for inserting andretracting a vision tube 12 comprised of block type lenses and asmall-sized camera employs a convenient and lightweight structureinstead of the structure of a conventional voluminous anddifficult-to-install retracting device, so a general user can easilyinstall the device. Additionally, with a spring 13, in the case of anabnormal situation, such as a repair/checkup, a power failure or theinterruption of compressed air, a signal generated in a control box 14is sent to an electric locking device 15 using a solenoid, so the visiontube 12 is automatically retracted in a motor-less manner, thuspreventing the causes of breakdown generated when the vision tube 12 isretracted using power.

[0066] In addition, the present invention allows high performanceproducts to be manufactured and provided at low costs, so the inside ofa furnace used in an iron mill, a cement factory, an incinerator and apower plant can be continuously monitored and the reliability andquality of products are improved, thus significantly developingindustrial furnace industry.

1. In a system for monitoring an inside of a furnace inaccessible to anoperator through a hole formed in a wall of the furnace, a motor-lessautomatic retraction device, comprising: a wall sleeve for cooling andprotecting a vision tube by being brought into contact with a flange toprevent compressed supplied from a control box and discharging thecompressed air through a space between the inside of the furnace and thevision tube; a locking device designed to be interlocked with a latchfastened to a vision tube bracket at the time of being inserted into thefurnace so as to prevent the vision tube from being randomly retractedby elasticity of the spring, and to allow automatic retraction byautomatically releasing the vision tube from interlocking with theelectric locking device in response to a signal from a control box at anabnormal situation, such as switch manipulation of an operator forautomatic retraction, a power failure or pressure reduction of thecompressed air; and a shock absorber for buffering impact when thevision tube is inserted into the inside of the furnace with a carriageplate attached to a rail and retracted from the inside of the furnace bya spring.
 2. The motor-less automatic retraction device as set forth inclaim 1, wherein the spring used to automatically retract the visiontube is a mainspring.
 3. The motor-less automatic retraction device asset forth in claim 1, wherein the spring used to automatically retractthe vision tube is a coil spring.
 4. In a motor-less automaticretraction device of claim 1, an electric locking device adapted tofunction to prevent the vision tube from being randomly retracted byelasticity of the spring by being interlocked with a latch fastened to avision tube bracket at the time of being inserted into the furnace, andto allow the motor-less automatic retraction device to be operated byreceiving a signal from a control box at an abnormal situation such asswitch manipulation of an operator for automatic retraction, a powerfailure or pressure reduction of compressed air and unlocking theelectric locking device and the latch.